border-1px($color) {
  position relative

  &:after {
    display block
    position absolute
    left 0
    bottom 0
    width 100%
    border-top 1px solid $color
    content ' '
  }
}

border-none() {
  &:after {
    display none
  }
}
bg-image($url) {
  background-image url($url + "@2x.png")

  @media (-webkit-min-device-pixel-ratio: 3), (min-device-pixel-retio: 3) {
    background-image url($url + "@3x.png")
  }
}
